Heat-transfer apparatus



H. ZIMMERMANN.

HEAT TRANSFER APPARATUS.

APPLICATION FILED APR. 3, 1918.

Patented Apr. 27,' 1920.

IN VENTOR IIATTORNEYS HANS ZIMMERMANN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO SCHUTTE AND KOERTING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.

HEAT-TRANSFER APPARATUS.

Patented Apr.27,192o.

Application filed April 3, 1918. Serial No. 226,352.

To all wk om it may concern Be it known that I, Hans ZIMMERMANN, a subject of the German Empire, residing in the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Heat-Transfer Apparatus, of which the following is a true and exact description, reference being had to the accompanying drawings, which form a part thereof.

My present invention consists in an improvement in heat interchanging apparatus of the type in which a heat transfer is effected between a fluid in contact with the inner walls, and another fluid in contact with the outer walls of a group of tubes. The general object of the invention is to provide simple and effective apparatus of the kind for the purpose described adapted for operation under conditions in which a high capacity per unit of bulk and weight of apparatus is required.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention however and the advantages possessed by it reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described preferred embodiments of my invention.

. Of the drawings,

Figure 1 is a plan view of a heat interchanging device.

Fig. 2 is a longitudinal section of the device shown in Fig. 1.

.Fig. 3 is a transverse section taken on the line 3-3 of Fig. 1.

Fig. 4 is a transverse section illustrating a modified construction. the section being taken on the line 44 of Fig. 5; and

Fig. 5 is a partial longitudinal section taken at right angles to Fig. 4.

In the drawings. and referring first to the construction shown in Figs. 1, 2 and 3. A represents the cylindrical casing body of a heat interchanging device, embodying my present invention. and primarily devised for use as an air cooling device on submarines. and under other conditions in which relatively high capacity as compared with the weight and bulk of the apparatus is required. Secured to the flanged ends of the cylindrical casing body A are chambered end members or heads B. As shown, the end members are secured to the body member by bolts C. D represent tube sheets or plates to which the opposite ends of tubes E are secured. Each'tube sheet is surrounded and has a sliding fit in an annular member G clamped between the corresponding end member B and adjacent end of the casing body. Packing rings F are compressed in grooves formed between each side of the member G at its inner edge and the adjacent casing part. This insures tight joints, while, at the same time, permitting freedom for. axial movement of the tube sheets D relative to the inclosing casing to accommodate relative thermal expansion and contraction of the parts.

One 'of the two fluids passing through the apparatus, for instance, the cooling water, when the apparatus is used as an air cooler, is admitted to one of the chambered end members, passes from the latter tothe other end member through the tubes E. The other fluid, air, when the device is used as an air cooler, is admitted to the intertube space through the inlet opening A formed in the wall of the casing body A adjacent one end of the latter, and passes out of the intertube spaces through an opening A in the casing wall body adjacent the opposite end of the latter. The

air is caused to fiow in a zigzag path, and with a desirable uniformity of velocity across the tubes by means of baffle plates I and J and flow guiding members H. The bafiie plates I are formed with one rounded end fitting snugly against the cylindrical inner wall of the casing body A at one side of the latter. The opposite end of each baffle plate I is spaced away from the adjacent portion of the cylindrical inner wall of the casing body A to permit the fiuid to pass over the end of the bafiie plate from one side tothe other of the latter. The battle plates J alternate with the bafiie plates I and are similar in shape to the latter but have their rounded ends bearing against the opposite side of the inner wall of the casing body. The bafile plates I and J are of course formed with apertures through which the tubes E pass. The flow guiding members H are in the form of parallel plates fitting snugly against the o posite side edges of the bafiies I and J. he edges of the members H are machlned at H, to fit snugly against the inner wall I y velocity and'in practically uniform volume across-each of the different tubes. This results from the uniformity ofspacing and I the relative arrangement of the baffle plates and flow guide members H, which insure a flow path of practically uniform crosssection through the intertube space notwithstanding the cylindrical bore of the casing body A. This arrangement makes possible the high flow velocities and effective utilization of all the exposed tube surfaces, which is required for high capacity small bulk apparatus. While it would be possible to obtain the same uniform flow path without the use of the special flow guiding members H, by making the bore of the casing body A rectangular in cross-section, this is not practically feasible with the kind of apparatus in which my invention is employed on account of the increased cost of production particularly in view of the relatively high internal pressures experienced in the service for which thisapparatus was especially devised, and the difiiculty of obtaining sufficient strength with a rectangular casing. The use of'a rectangular casing would also materially increase the difiiculty of obtaining tight oints while at the same time avoidin expansion and contraction troubles.

The baffle plates should be held against movement along the tubes and this may be accomplished in known ways as by soldering the bafiies -and tubes together, or by the use of tubular spacers as disclosed in my prior patent No. 1,168,368. Advantageously in some cases the bafiies may be held against axial displacement by entering their side edges in grooves formed in the flow guide members. Thus, -in the construction shown in Figs. 4 and 5 I have shown the opposite side edges of the baffle plates received in grooves H formed in the inner faces of the flow guide members HA. Aside from the feature just referred, the construction shown in Figs. 4.- and 5 differs from that shown in Figs. 1, 2 and 3 only in that the tube rows are differently arranged, and the flow guide members HA are formed with longitudinal ribs H which enter the spaces between tubes in rows adjacent the members in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the annexed claims and that under some conditions certain features of my invention may some times be used with advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is,

1. In heat interchanging apparatus, the combination with a cylindrical casing of a bank of tubes longitudinally disposed in said casing and so grouped as to leave clear spaces unoccupied by tubes on opposite sides ofthe cylinder and flow guide members at said opposite sides of the cylinder and of the bank of tubes and transverse baffles providing a zigzag path of flow back and forth across the tubes of approximately uniform cross-section at all points in the intertube space. Y

2. In. heat interchanging apparatus, the combination with a cylindrical casing, of tubes longitudinally disposed in said casing and arranged in a bank having two of its opposite sides flat and parallel, flow guiding members interposed between the flat sides of the banks of tubes and the adjacent portions of the inner wall of the casing and baffle plates extending transversely to the tubes between the flow guiding members and having their opposite side edges in contact with said flow guiding members arranged to provide a zigzag path through the intertube space repeatedly traversing the tubes and leading from one end of the casing to the other. I 3. In heatinterchanging apparatus, the combination with a cylindrical casing, of tubes longitudinally disposed in said casing and arranged in a bank having two of its opposite sides flat and parallel, flow guiding members interposed between the fiat sides of the banks of the tubes and the adjacent portions of the inner wall of the casing and bafile plates extending transversely to the tubes between the fiow' guiding members and having their opposite side edges in contact with said flow guiding members arranged to provide a zigzag path through the intertube space repeatedly traversing the tubes and leading from one end of the casing to the other, said flow guiding members having longitudinal ribs entering spaces between the tubes.

4. In heat interchanging apparatus, the

tubes longitudinally disposed in said casing in a bank having opposite sides flat and parallel, baflle plates extending transversely to the tubes, fioW guiding members interposed between the flat sides of the banks'of-tubes and the adjacent portions of the inner Wall of the casing,and having their sides adjacent the tubes notched to receive adjacent edges of the baffles, said bafiies and flow 10 members being arranged to provide a zigzag path through the intertube space, repeatedly traversing the tubes and leading from one end of the casing to the other.

HANS ZIMMERMANN. 

